JP2014217978A - Metal laminate production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal laminate production method capable of producing a metal laminate having excellent appearance by reducing poor appearance such as a wrinkle during laminate or the like.SOLUTION: Provided is the production method of a metal laminate 4 in which a metal foil 1 and a heat deposition film 2 are subjected to continuous compression heating molding by disposing a protection film 3 between a compression surface of a compression heating molding device 5 and the metal foil by using the compression heating molding device 5, and then, from a laminate of the metal foil 1 and the heat deposition film 2, the protection film 3 is released for producing the metal laminate 4. Surface roughness Rz (μm) of the surface of the protection film 3 which contacts to the metal foil 1 is 2.0 or more and 6.0 or less.

Description

  The present invention relates to a method for manufacturing a metal laminate. More specifically, the present invention relates to a method for manufacturing a metal laminate plate that is suitably used for electronic and electrical equipment.

  As a typical example of a laminated board used for an electronic / electrical equipment printed circuit board, there is a flexible printed circuit (hereinafter abbreviated as FPC). The metal laminate used for FPC is a foldable laminate composed of a metal layer and a film layer. For example, a copper clad laminate such as a copper clad polyimide film in which a copper foil and a polyimide base film are laminated (Copper Clad Laminate, (Hereinafter abbreviated as CCL).

  CCL includes, for example, an inexpensive three-layer type composed of three layers of copper foil, an epoxy-based thermosetting adhesive layer and a polyimide base film, and two layers composed of two layers of copper foil and a polyimide base film. There is a three-layer type composed of three layers of a copper foil, a polyimide adhesive layer and a polyimide base film. The type using a polyimide adhesive layer may be a pseudo two-layer type because both the adhesive layer and the base film are polyimide.

  As a method for producing a two-layer CCL, a method of directly plating copper on a polyimide base film (plating two-layer CCL), a method of forming a polyimide base film by applying polyamic acid to a copper foil, drying and imidizing (Cast 2 layer CCL). As a method for producing a pseudo two-layer CCL, a method of laminating a polyimide base film having a polyimide adhesive layer formed on a surface thereof with a copper foil (laminate two-layer CCL) is known.

  Several methods have been proposed for the production of the laminate two-layer CCL. For example, there is a method of bonding a polyimide adhesive in a sandwich between a polyimide base film and a copper foil using a vacuum press machine or the like as a laminating apparatus. A method of continuously laminating using a hot roll laminator has also been proposed. The latter method is advantageous in that a long product can be obtained.

  As a method to prevent wrinkling during lamination, a protective material is placed between the pressure surface of the pressure heating molding device and the material to be laminated, pressure thermoforming is performed, and the protective material is peeled off from the laminate after cooling. Has been proposed (see, for example, Patent Document 1). However, this method has a problem in that an appearance defect occurs when the protective film is peeled off. In contrast, a method in which the adhesion strength at the interface between the protective material and the material to be laminated is in the range of 0.1 to 3 N / cm (see, for example, Patent Document 2), and after cooling, the protective material is peeled off sequentially one by one A method (for example, see Patent Document 3) and a method for physically treating and using the surface of a protective film (for example, see Patent Document 4) have been proposed. However, even when these methods are used, when the laminating temperature is increased, it is not possible to sufficiently prevent the appearance defect that occurs when the protective film is peeled off.

JP 2001-129918 A JP 2002-370281 A JP 2003-31882 A JP 2007-109694 A (Claim 4)

  In view of the above problems, an object of the present invention is to provide a metal laminate sheet that reduces defects in appearance such as wrinkles and has a good appearance efficiently.

  In the present invention, a metal foil and a heat-weldable film are continuously pressed by using a pressure heating molding apparatus and a protective film disposed between the pressing surface of the pressure heating molding apparatus and the metal foil. It is a manufacturing method of the metal laminated board which peels a protective film from the laminated body of metal foil and a heat weldable film after heat-molding, Comprising: Surface roughness Rz (micrometer) of the surface which touches the metal foil of a protective film, It is a manufacturing method of the metal laminated board characterized by being 2.0 or more and 6.0 or less.

  By using the method for producing a metal laminate of the present invention, it is possible to obtain a metal laminate having a good appearance with little occurrence of wrinkles even when a flexible metal foil that tends to cause appearance defects such as wrinkles is used. Therefore, the present invention provides a material suitable as a metal laminated plate for electronic and electronic equipment.

It is the schematic which shows an example of the manufacturing method of the metal laminated sheet of this invention.

  Details of the present invention will be described below.

  In the method for producing a metal laminate of the present invention, a protective film is disposed between a pressing surface of the pressure heating molding apparatus and the metal foil using a pressure heating molding apparatus. A method for producing a metal laminate in which a protective film is peeled off from a laminate of a metal foil and a heat-weldable film after being continuously pressurized and heated, and the surface roughness of the surface in contact with the metal foil of the protective film The thickness Rz (μm) is 2.0 or more and 6.0 or less.

  The metal foil used in the present invention is not particularly limited as long as it can be used for a metal laminate for electronic and electrical equipment, but is preferably a copper foil, generally a rolled copper foil having a thickness of 3 to 50 μm, Examples include electrolytic copper foil.

  Moreover, in this invention, it is preferable that the surface which contact | connects the protective film of metal foil is processed with organic substance. Examples of organic treatment methods include rust prevention treatment, bumping treatment, and easy adhesion treatment. Moreover, the said organic substance process may be carried out also about the surface which contact | connects the heat weldable film of metal foil.

  Moreover, in this invention, it is preferable that the surface roughness Rz (micrometer) of the surface which touches the protective film of metal foil is 1.0 micrometer or less. When the surface roughness Rz (μm) is 1.0 μm or less, wrinkles during lamination can be further suppressed and the appearance can be further improved. Furthermore, from the point which has moderate adhesiveness with a protective film, 0.8 micrometer or less is more preferable.

  Moreover, in this invention, it is preferable to have metal foil on both surfaces of a weldable film. Thereby, the tension | tensile_strength at the time of peeling is stabilized and an external appearance is improved more.

  The heat-weldable film used in the present invention is not particularly limited as long as it is a film that can be bonded to a metal foil by pressure and thermoforming. However, a non-thermoplastic resin layer is used as a base, and a heat-bonding film as a bonding layer to the metal foil is used. A film in which a plastic resin layer is laminated is common. For example, the laminated body which has a thermoplastic polyimide layer on both surfaces of a non-thermoplastic polyimide layer is mentioned. Here, non-thermoplastic refers to those having no glass transition temperature below the decomposition temperature of the resin, and thermoplastic refers to those having a glass transition temperature below the decomposition temperature of the resin.

  The non-thermoplastic polyimide layer preferably has a thickness of 5 to 200 μm. The surface of the non-thermoplastic polyimide layer is preferably subjected to surface treatment such as hydrolysis, corona discharge, low-temperature plasma, physical roughening, and easy adhesion coating treatment. Thereby, adhesiveness with metal foil improves more.

  The thermoplastic polyimide layer is composed of a polyimide-based adhesive composition such as a solvent-soluble polyimide composition, a silicone diamine-containing polyimide composition, or a hybrid composition in which an epoxy composition is mixed therewith. A layer can be exemplified. Furthermore, various additives may be blended in the thermoplastic polyimide layer in order to improve various properties. The thickness of the thermoplastic polyimide layer is preferably 1 to 6 μm. Thereby, adhesiveness with metal foil and a dimensional change rate improve more.

  Further, the thermoplastic polyimide layer preferably has a glass transition temperature of 200 ° C. or higher, and more preferably 230 ° C. or higher. When the glass transition temperature is 200 ° C. or higher, softening does not occur due to heating at the time of electronic component mounting, dimensional stability is improved, and mounting defects can be reduced. The glass transition temperature is preferably 300 ° C. or lower, and more preferably 280 ° C. or lower. If glass transition temperature is 300 degrees C or less, since lamination temperature can be made low, it will become difficult to wrinkle by thermal expansion.

  The method for producing the heat-welding film is not particularly limited, and examples thereof include a multilayer extrusion film-forming method in which several types of layers are formed at once, and a coating method in which other layers are sequentially formed on a non-thermoplastic polyimide film. As a coating method, various methods such as a gravure coater, a comma coater, a reverse coater, a bar coater, and a slit die coater can be used according to the physical properties of the coating material.

  The protective film used in the present invention is not particularly limited as long as the surface roughness Rz (μm) of the surface of the protective film in contact with the metal foil is 2.0 or more and 6.0 or less. For example, a polyimide film or an aramid film Can be mentioned. The surface roughness Rz (μm) is more preferably 3.0 or more and 5.0 or less.

  Moreover, since the uniformity of the surface pressure of metal foil and a protective film is maintained because Rz (micrometer) is 2.0 or more and 6.0 or less in the protective film used for this invention, a surface is not roughened. Appearance is kept good. Moreover, since the surface roughness Rz (micrometer) of the surface which touches the metal foil of a protective film is 2.0 or more and 6.0 or less, the protective film used for this invention can make a lamination speed | rate high.

  When the laminating speed is increased, the time required for heat application to the heat-weldable film is shortened. Therefore, heating at a higher temperature is required for heat-welding. For example, when the laminating speed is 4 m / min, the laminating temperature needs to be 360 ° C. in order to bond the metal foil and the heat-welding film. However, when heated at a high temperature, there is a problem that wrinkles are easily generated in the metal foil when the protective film is peeled off. In the method for producing a metal laminate of the present invention, the surface roughness Rz (μm) of the surface in contact with the metal foil of the protective film is 2.0 or more, thereby reducing the adhesion between the metal foil and the protective film. Therefore, the peeling force in peeling off the protective film is reduced, and it is possible to suppress the occurrence of wrinkles or warpage on the surface of the metal foil of the resulting metal laminate.

  Moreover, it is preferable that the manufacturing method of the metal laminated plate of this invention is 4 m / min or more in the lamination speed | rate at the time of carrying out pressurization heating molding continuously. If the lamination speed is 4 m / min or more, the production efficiency can be further increased. Moreover, it is preferable that the lamination speed | rate at the time of carrying out a pressurization heating molding is 10 m / min or less. If it is 10 m / min or less, it can suppress more that wrinkles generate | occur | produce on the metal foil surface of the metal laminated board obtained, or a curvature generate | occur | produces.

  The method for setting the surface roughness Rz (μm) of the protective film to 2.0 or more and 6.0 or less is not particularly limited, but generally includes a sand mat treatment.

  Moreover, a metal laminated board can be manufactured more cheaply by repeatedly using a protective film. Therefore, the thickness of the protective film is preferably 25 μm or more, and more preferably 50 μm or more. When the thickness of the protective film is 25 μm or more, the protective film can be used again and again.

  In the present invention, it is preferable to use a laminating apparatus having at least a pair of metal rolls as the pressure heating molding apparatus. Furthermore, it is preferable to provide a winding shaft for each laminated material and protective film, a product, and a winding shaft for the protective film. For example, a hot roll laminating machine, a double belt press machine, etc. are mentioned, Among these, a hot roll laminating machine having at least one pair of metal rolls is preferably used. The method for heating the metal roll is not particularly limited as long as it can be heated at a predetermined temperature, and examples thereof include a heat medium circulation method, a hot air heating method, and a dielectric heating method. The pressurization method is not particularly limited as long as a predetermined pressure can be applied, and includes a hydraulic method, a pneumatic method, a gap pressure method, and the like, and the pressure is not particularly limited. In addition, as equipment that enables continuous lamination, tension control device, line adjustment device (EPC), etc., as well as cleaning equipment to maintain the quality as electronic circuit materials, adhesive rolls, static eliminator, A clean booth can be used as necessary.

  Moreover, when the protective film is peeled from the laminated body of metal foil and a heat-welding film, it is preferable to peel the manufacturing method of the metal laminated board of this invention using an expander roll. By using the expander roll, the peeling start portion can be stabilized.

  Hereafter, the manufacturing method of the metal laminated sheet of this invention is demonstrated using FIG. 1 as an example. FIG. 1 is a schematic view showing an example of a method for producing a metal laminate of the present invention. The metal foil 1 is continuously pressed and heated by a pair of laminate rolls 5 through the protective film 3 on both surfaces of the heat-welding film 2. After pressurization and heating, the protective film 3 is peeled off by the peeling roll 6 and the product 4 is wound up.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. It shows about the copper foil and protective film which were used by each following example and comparative example.

<Copper foil>
BHY-22B-T: protective film side surface roughness (Rz) 0.7 μm, thickness 12 μm, protective film side organic matter treatment, JX Nippon Mining & Metals HLB: protective film side surface roughness (Rz) 2 μm, thickness 12 μm, no protection film side organic matter treatment, HD-12 manufactured by Nihon Electrolytic Co., Ltd .: protection film side surface roughness (Rz) 1.3 μm, thickness 12 μm, protection film side organic matter treatment, Fukuda Metal Foil Powder Industrial Co., Ltd. Company BHY-22B-HA: protective film side surface roughness (Rz) 0.9 μm, thickness 12 μm, with protective film side organic matter treatment, manufactured by JX Nippon Mining & Metals Co., Ltd. <Protective film>
300H: Polyimide film, manufactured by Toray DuPont Co., Ltd. Further, the protective film, the surface roughness Rz (μm) of the copper foil, and the appearance of the obtained metal laminate were evaluated by the following methods.

<Protective film, surface roughness Rz (μm) of copper foil>
According to JIS B0601 (1994), the 10-point average roughness of the surface in contact with the metal foil was measured for the protective film, and the 10-point average roughness of the surface in contact with the protective film was measured for the copper foil. Here, the cutoff value was 0.08 mm, and the reference length was 100 mm.

<Appearance of metal laminate>
The surface of the metal laminate was visually observed, and the presence or absence of defects such as laminate wrinkles, horizontal rows, protective film peeling wrinkles, and surface roughness was evaluated. Here, the peeling wrinkle of the protective film means a crease generated when the protective film is peeled off, and is generated when the peeling state is unstable. In Tables 1 and 2, those having no such defects are indicated by ◎ (1 or less per 100 m of peeling wrinkles), and those having some peeling wrinkles and those having no practical problems are indicated by ○ (1 to 100 m per peeling wrinkle). 10), and the ones with peeling wrinkles that had problems in appearance or practical use were expressed as x (10 or more per 100 m peeling wrinkles). Surface roughness with no defects ◎ (no surface roughness), no problem in practical use, but some surface roughness occurs ○ (surface roughness only on the metal foil surface), surface roughness with practical problems What was generated was expressed as x (surface roughness on the surface of the metal foil and the heat-sealing film).

Example 1
Preparation of metal laminate plate To a reaction kettle equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device using hot water / cooling water, and a stirring device, 3,3 ′, 4,4′-bisphenyltetracarboxylic 4 mol and 3,3 ′, 4,4′-oxy-bisphenyltetracarboxylic anhydride 0.6 mol together with 2377 g of n-methylpyrrolidone were dissolved, and then 4,4′-oxy-bis-benzenediamine 1 0.0 mol was added and reacted at 70 ° C. for 4 hours to obtain a polyamic acid solution. 200 g of toluene was added to the obtained polyamic acid solution, heated at 200 ° C., and an imidization reaction was performed for 3 hours while separating water azeotroped with toluene as the reaction progressed. Thereafter, toluene was distilled off, and the obtained polyimide varnish was poured into water, and the resulting precipitate was separated, ground, washed and dried to obtain a polyimide powder. 500 g of the obtained polyimide powder was added to 2834 g of dimethylacetamide and stirred at 40 ° C. for 2 hours to obtain a polyimide solution. Each of the obtained polyimide solutions was applied to “Kapton (registered trademark)” EN (manufactured by Toray DuPont Co., Ltd.) and then dried at 200 ° C. for 30 minutes to produce a heat-weldable film.

  Using the heat-weldable film obtained above, a metal laminate was produced using the hot roll laminator shown in FIG. The copper foil, the protective film, the lamination conditions, and the peeling roll used are as shown in Table 1. The results of evaluating the appearance of the obtained metal laminate are shown in Table 1. The protective film was subjected to a sand matte treatment so that the surface roughness (Rz) was 2.8 μm.

Examples 2-9, Comparative Examples 1-4
A metal laminate was prepared in the same manner as in Example 1 except that the copper foil, protective film, lamination conditions, and peeling roll used were as shown in Table 1. The results of evaluating the appearance of the obtained metal laminate are shown in Tables 1 and 2.

DESCRIPTION OF SYMBOLS 1 Metal foil 2 Heat welding film 3 Protective film 4 Product 5 Laminating roll 6 Peeling roll

Claims (6)

After the metal foil and the heat-weldable film are continuously pressure-heat-molded by using a pressure-heating molding device and placing a protective film between the pressing surface of the pressure-heating molding device and the metal foil. A method for producing a metal laminate in which a protective film is peeled from a laminate of a metal foil and a heat-weldable film, and the surface roughness Rz (μm) of the surface of the protective film in contact with the metal foil is 2.0 or more The manufacturing method of the metal laminated board characterized by being 6.0 or less. The method for producing a metal laminate according to claim 1, wherein the surface of the metal foil in contact with the protective film is treated with an organic substance. The method for producing a metal laminate according to claim 1 or 2, wherein a laminating speed at the time of continuous pressure and heat forming is 4 m / min or more. The surface roughness Rz (micrometer) of the surface which touches the protective film of metal foil is 1.0 micrometer or less, The manufacturing method of the metal laminated sheet in any one of Claims 1-3 characterized by the above-mentioned. The method for producing a metal laminate according to any one of claims 1 to 4, further comprising metal foil on both surfaces of the heat-weldable film. The method for producing a metal laminate according to any one of claims 1 to 5, wherein when the protective film is peeled off from the laminate of the metal foil and the heat-welding film, the protective film is peeled off using an expander roll.

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